Dual-axis adaptive optic (AO) system for high-power lasers

Abstract

A system includes a master oscillator configured to generate a low-power optical beam. The system also includes a planar waveguide (PWG) amplifier configured to generate a high-power optical beam using the low-power optical beam. The PWG amplifier has a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction. The system further includes at least one adaptive optic (AO) element configured to modify the low-power optical beam along the slow-axis direction and to modify the low-power optical beam along the fast-axis direction. In addition, the system includes a feedback loop configured to control the at least one AO element. The modification in the slow-axis direction can compensate for thermal-based distortions created by the PWG amplifier, and the modification in the fast-axis direction can compensate for optical misalignment associated with the master oscillator and the PWG amplifier.

What is claimed is: 
     
       1. A system comprising:
 a master oscillator configured to generate a first optical beam; 
 a planar waveguide (PWG) amplifier configured to generate a second optical beam using the first optical beam, the second optical beam having a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; 
 at least one adaptive optic (AO) element configured to modify the first optical beam along the slow-axis direction and to modify the first optical beam along the fast-axis direction; and 
 a feedback loop configured to control the at least one AO element; 
 wherein the at least one AO element is configured to modify the first optical beam along the slow-axis direction in order to compensate for thermal-based distortions created by the PWG amplifier; and 
 wherein the at least one AO element is configured to modify the first optical beam along the fast-axis direction in order to compensate for optical misalignment associated with the master oscillator and the PWG amplifier. 
 
     
     
       2. The system of  claim 1 , wherein the feedback loop comprises:
 one or more sensors configured to generate measurements of multiple characteristics of samples of the second optical beam; and 
 a controller configured to control the at least one AO element based on the measurements. 
 
     
     
       3. The system of  claim 1 , wherein each AO element comprises one of: a deformable mirror, a liquid crystal-based optical phased array, a spatial light modulator, and a steering mirror. 
     
     
       4. A system comprising:
 a master oscillator configured to generate a first optical beam; 
 a planar waveguide (PWG) amplifier configured to generate a second optical beam using the first optical beam, the second optical beam having a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; 
 at least one adaptive optic (AO) element configured to modify the first optical beam along the slow-axis direction and to modify the first optical beam along the fast-axis direction; and 
 a feedback loop configured to control the at least one AO element; 
 wherein the feedback loop comprises a first control loop configured to control the modification of the first optical beam along the slow-axis direction and a second control loop configured to control the modification of the first optical beam along the fast-axis direction; and 
 wherein the first and second control loops are configured to use measurements of different characteristics of samples of the second optical beam. 
 
     
     
       5. The system of  claim 4 , wherein the first and second control loops are configured to operate at different frequencies or intervals. 
     
     
       6. The system of  claim 4 , wherein:
 the first and second control loops are configured to operate at similar frequencies; and 
 the first control loop is configured to consider changes to the first optical beam caused by the second control loop. 
 
     
     
       7. A system comprising:
 a master oscillator configured to generate a first optical beam; 
 a planar waveguide (PWG) amplifier configured to generate a second optical beam using the first optical beam, the second optical beam having a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; 
 multiple adaptive optic (AO) elements configured to modify the first optical beam along the slow-axis direction and to modify the first optical beam along the fast-axis direction; and 
 a feedback loop configured to control the multiple AO elements; 
 wherein the multiple AO elements are configured to correct both translational and angular misalignment associated with the master oscillator and the PWG amplifier. 
 
     
     
       8. A method comprising:
 generating a first optical beam using a master oscillator; 
 amplifying the first optical beam to generate a second optical beam using a planar waveguide (PWG) amplifier, the second optical beam having a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; 
 using at least one adaptive optic (AO) element, modifying the first optical beam along the slow-axis direction and along the fast-axis direction; and 
 controlling the at least one AO element using a feedback loop; 
 wherein modifying the first optical beam comprises:
 modifying the first optical beam along the slow-axis direction in order to compensate for thermal-based distortions created by the PWG amplifier; and 
 modifying the first optical beam along the fast-axis direction in order to compensate for optical misalignment associated with the master oscillator and the PWG amplifier. 
 
 
     
     
       9. The method of  claim 8 , wherein controlling the at least one AO element using the feedback loop comprises:
 obtaining measurements of multiple characteristics of samples of the second optical beam from one or more sensors; and 
 controlling the at least one AO element based on the measurements. 
 
     
     
       10. The method of  claim 9 , wherein:
 the one or more sensors comprise a two-dimensional camera; 
 one dimension of the camera corresponds to the slow-axis direction; and 
 an orthogonal dimension of the camera corresponds to the fast-axis direction. 
 
     
     
       11. A method comprising:
 generating a first optical beam using a master oscillator; 
 amplifying the first optical beam to generate a second optical beam using a planar waveguide (PWG) amplifier, the second optical beam having a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; 
 using at least one adaptive optic (AO) element, modifying the first optical beam along the slow-axis direction and along the fast-axis direction; and 
 controlling the at least one AO element using a feedback loop; 
 wherein the feedback loop comprises a first control loop that controls the modification of the first optical beam along the slow-axis direction and a second control loop that controls the modification of the first optical beam along the fast-axis direction; and 
 wherein the first and second control loops use measurements of different characteristics of samples of the second optical beam. 
 
     
     
       12. The method of  claim 11 , wherein the first and second control loops operate at different frequencies or intervals. 
     
     
       13. The method of  claim 11 , wherein:
 the first and second control loops operate at similar frequencies; and 
 the first control loop considers changes to the first optical beam caused by the second control loop. 
 
     
     
       14. The method of  claim 11 , wherein:
 the first control loop controls the modification of the first optical beam along the slow-axis direction based on at least one of: wavefront sensor measurements, power-in-the-bucket sensor measurements, and linear array sensor measurements; and 
 the second control loop controls the modification of the first optical beam along the fast-axis direction based on output power sensor measurements. 
 
     
     
       15. A method comprising:
 generating a first optical beam using a master oscillator; 
 amplifying the first optical beam to generate a second optical beam using a planar waveguide (PWG) amplifier, the second optical beam having a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; 
 using multiple adaptive optic (AO) elements, modifying the first optical beam along the slow-axis direction and along the fast-axis direction; and 
 controlling the multiple AO elements using a feedback loop; 
 wherein the multiple AO elements correct both translational and angular misalignment associated with the master oscillator and the PWG amplifier. 
 
     
     
       16. An apparatus comprising:
 at least one interface configured to receive measurements of samples of a second optical beam generated by a planar waveguide (PWG) amplifier using a first optical beam generated by a master oscillator such that the second optical beam has a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; and 
 at least one processing device configured to:
 control one or more first adaptive optic (AO) elements to modify the first optical beam along the slow-axis direction; and 
 control one or more second AO elements to modify the first optical beam along the fast-axis direction. 
 
 
     
     
       17. An apparatus comprising:
 at least one interface configured to receive measurements of samples of a second optical beam generated by a planar waveguide (PWG) amplifier using a first optical beam generated by a master oscillator such that the second optical beam has a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; and 
 at least one processing device configured to control at least one adaptive optic (AO) element to:
 modify the first optical beam along the slow-axis direction in order to compensate for thermal-based distortions created by the PWG amplifier; and 
 modify the first optical beam along the fast-axis direction in order to compensate for optical misalignment associated with the master oscillator and the PWG amplifier. 
 
 
     
     
       18. An apparatus comprising:
 at least one interface configured to receive measurements of samples of a second optical beam generated by a planar waveguide (PWG) amplifier using a first optical beam generated by a master oscillator such that the second optical beam has a higher power than the first optical beam, the PWG amplifier having a larger dimension in a slow-axis direction and a smaller dimension in a fast-axis direction; and 
 at least one processing device configured to control at least one adaptive optic (AO) element to modify the first optical beam along the slow-axis direction and along the fast-axis direction; 
 wherein the at least one processing device is configured to form part of a first control loop that controls the modification of the first optical beam along the slow-axis direction and part of a second control loop that controls the modification of the first optical beam along the fast-axis direction; and 
 wherein the at least one processing device is configured to use measurements of different characteristics of the samples for the different control loops. 
 
     
     
       19. The apparatus of  claim 18 , wherein the first and second control loops are configured to operate at different frequencies or intervals. 
     
     
       20. The apparatus of  claim 18 , wherein:
 the first and second control loops are configured to operate at similar frequencies; and 
 the first control loop is configured to consider changes to the first optical beam caused by the second control loop. 
 
     
     
       21. The apparatus of  claim 18 , wherein the at least one processing device is configured to:
 control one or more first AO elements to modify the first optical beam along the slow-axis direction; and 
 control one or more second AO elements to modify the first optical beam along the fast-axis direction. 
 
     
     
       22. The system of  claim 2 , wherein:
 the feedback loop comprises (i) a first control loop configured to control the modification of the first optical beam along the slow-axis direction and (ii) a second control loop configured to control the modification of the first optical beam along the fast-axis direction; and 
 the first and second control loops are configured to use measurements of different characteristics of the samples. 
 
     
     
       23. The system of  claim 1 , wherein the feedback loop is configured to:
 control one or more first AO elements to modify the first optical beam along the slow-axis direction; and 
 control one or more second AO elements to modify the first optical beam along the fast-axis direction.